Self-feeding trowel



Feb. 13, 1968 E. E. EDENs, .1R

SELF-FEEDING TROWEL Filed Aug. 8, 1966 United States Patent 3,368,234 SELF-FEEDING TRGWEL Edgar Earl Edeus, Jr., La Puente, Calif., assiguor to Trowel Fast, Inc., Azusa, Calif., a corporation of California Filed Aug. 8, 1966, Ser. No. 570,796 Claims. (Ci. 401--263) ABSTRACT 0F THE DISCLOSURE A plastererls trowel the troweling surface of which is provided with plaster discharge openings located different distances from the forward edge of the trowel, and

having a selector valve for delivering plaster to such discharge openings selectively. When troweling adjacent an edge of a wall, such as adjacent a ceiling, plaster may be fed to a discharge opening adjacent the forward edge of the trowel. When troweling away from the edges of the wall, the plaster may be delivered to` one or more discharge openings adjacent the center of the troweling surface. Thus, plaster can be delivered to that portion of the troweling surface which best meets the requirements of the particular troweling operation being performed.

The present invention relates to a self-feeding trowel, i.e., a trowel having means for feeding plaster to the troweling surface of the blade thereof. The term plaster is used herein in a general sense to include any material, particularly a settable cementitious material, susceptible of application by troweling.

As background, prior self-feeding plastering trowels conventionally deliver the plaster to the troweling surface in the general vicinity of the center of such surface. This is quite satisfactory when troweling an area of a wall, for example, remote from the edges thereof. However, when utilizing -such a prior self-feeding trowel on a wall adjacent an edge thereof, e.g., yadjacent a ceiling of acoustical plaster, it is necessary to work the plaster fed to the troweling surface toward the edge of the wall because of the location of the plaster discharge point adjacent the center of the troweling surface. Working the plaster toward the edges of the wall under such conditions requires considerable additional effort.

Summary and objects of invention The present invention overcomes the foregoing disadvantage of prior self-feeding trowels by providing for selective feeding of plaster to different portions of the troweling surface, depending upon the particular troweling oper-ation being performed. For example, the invention feeds plaster to the troweling surface adjacent its forward edge when troweling the upper edge of a wall adjacenta ceiling of acoustical plaster, for example. This reults in delivery of the plaster at precisely the point on the troweling surface required for such a troweling operation, which is an important feature of the invention.

With the foregoing as background, the primary object of the invention is to provide the troweling surface with plaster discharge openings located.l different distances from the forward edge of the blade, and to provide the trowel with means for delivering plaster to `such discharge openings selectively. With this construction, when troweling adjacent a wall edge, plaster may be fed to a discharge opening adjacent the forward edge of the blade. When troweling a wall area remote from the edges of the wall, the plaster may be delivered to a discharge opening or openings adjacent the center of the troweling surface. Thus, the plaster can be delivered to that portion of the troweling surface which best meets the requirements 3,368,234 Patented Feb. 13, 1%68 of the particular troweling operation being performed, which is an important feature.

Another object of the invention is to provide a troweling blade having mounted thereon, on the side opposite its troweling surface, a plaster distributing means for delivering plaster to the discharge openings in the troweling surface selectively.

Still another object is to provide such a plaster distributing means which includes selector valve means for opening and closing the discharge openings in the troweling surface selectively.

Yet another object is to provide a plaster distributing means which includes a plaster manifold communicating with the discharge openings Iand containing the selector val-ve means.

An additional object is to provide a trowel wherein the discharge openings are spaced apart longitudinally of the troweling surface and are located in ya region bounded by substantially the longitudinal centerline of the blade and the trailing edge thereof.

A further object is to provide the troweling surface with a forward discharge opening adjacent the forward edge of the blade, a rearward discharge opening approximately midway between the forward and rearward edges of the blade, and an intermediate discharge opening intermediate the forward and rearward discharge openings and adjacent the forward discharge opening. A related object is to provide a selector `valve means for opening either the forward discharge opening only, or the rearward and intermediate discharge openings simultaneously. The trowel may be used for troweling adjacent a ceiling, or the like, when the selector valve means is positioned to open the forward discharge opening only. By positioning the selector valve means to close the forward discharge opening, and to open the rear-ward and intermediate discharge openings, the trowel may be used for applying plaster to 'a wall area remote from the edges of the wall.

Still another object of the invention is to provide the plaster manifold with a plaster inlet between the rearward and intermediate discharge openings and adjacent the intermediate discharge opening, and to make the intermediate discharge opening smaller than the rearward discharge opening. With this construction, the plaster flows to the intermediate and rearward discharge openings, when Isuch openings are in use, are approximately equal.

Yet another, and important, object of the invention is to provide a plaster conduit, connected to the inlet of the plaster manifold, having a portion adjacent the plaster manifold which is more yieldable than the remainder of such conduit to provide a surge chamber adjacent the plaster manifold. Such surge chamber accommodates pressure surges resulting, for example, from starting a pla-ster pump to which the plaster conduit is connected.

The foregoing objects, advant-ages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will be evident to those skilled in the troweling art in the light of this disclosure, may be achieved with the exemplary embodiment of the invention described in detail hereinafter and illustrated in the vaccompanying drawing.

Description 0f drawing In the drawing:

FIG. 1 is Ia perspective view of one embodiment of a self-feeding trowel which embodies the invention;

FIG. 2 is a plan view of a troweling blade of the selffeeding trowel of FIG. l showing its troweling surface and discharge openings in such surface;

FIGS. 3 and 4 are enlarged, fragmentary, longitudinal sectional views taken along the arrowed line 3-3 of FIG. 1 and showing a selector valve means of a plaster distributing means of the invention in different operating positions;

FIG. 5 is a transverse sectional view taken as indicated by the arrowed line 5 5 of FIG. 3;

FIG. 6 is an enlarged perspective view of a slide valve forming part of the selector valve means of the self-feeding trowel of FIG. 1; and

FIG. 7 is a transverse sectional `View similar to FIG. 5, but illustrating another embodiment of the self-feeding trowel of the invention.

Description 0f preferred embodiment of invention The self-feeding trowel of the invention which is shown in FIGS. 1 to 6 of the drawing is designated generally by the numeral 10 and, as is conventional, includes a rectangular troweling blade 12 having a troweling or working surface 14 on one side thereof and a mounting surface 16 on its opposite side. Seated `against the mounting surface 16 and suitably secured to the blade 12 is a longitudinally-extending reinforcing rib 18 carrying a suitable handle 20 of a conventional type. The reinforcing rib 18 is preferably located substantially on the longitudinal centerline of the blade 12.

The rectangular troweling blade 12 provides at its end longitudinally -opposed forward and rearward edges 22 and 24 extending laterally thereof. The longer edges of the rectangular troweling blade 12 constitute laterallyopposed, longitudinally-extending leading and trailing edges 26 and 28. The terms leading and trailing are used with reference to the normal direction of movement of the trowel 1G over a surface being troweled by a right-handed operator. It will be understood that the leading and trailing edges 26 and 28 are reversed with a left-handed user.

As best shown in FIG. 2 of the drawing, the troweling surface 14 is provided therein with longitudinallyspaced forward, intermediate and rearward plaster discharge openings 30, 32 and 34 through which plaster is selectively delivered to the troweling surface in a manner to be described hereinafter. The forward discharge opening 30 is located adjacent the forward edge 22 of the blade 12, while the rearward discharge opening 34 is located approximately midway between the forward and rearward edges 22 and 24 of the blade. The intermediate discharge opening 32 is located between the forward and rearward discharge openings 30 and 34 and adjacent the forward discharge opening. Since, as will be discussed hereinafter, the ow of plaster to the trowel 10 is delivered either to the forward discharge opening 30 only, or to the intermediate and rearward discharge openings 32 and 34 simultaneously, the `area of the forward discharge opening is approximately equal to the combined areas of the intermediate and rearward discharge openings. Preferably, the forward `and rearward discharge openings 30 and 34 are longitudinally elongated. The intermediate discharge opening 32 is preferably smaller than the rearward discharge opening 34 for a reason to be discussed.

To insure delivery of plaster to the proper portion of the troweling surface 14, the discharge openings 30, 32 and 34 are all located in a region of the troweling surface bounded by substantially the longitudinal centerline of the blade 12 and the trailing edge 28 thereof, as clearly shown in FIG. 2. It will be understood that if the trowel 10 is intended for a left-handed user so that the leading and trailing edges 26 and 28 are rever-sed, the discharge openings 30, 32 and 34 will be located on the opposite side of the longitudinal centerline from that shown in FIG. 2.

Seated against the mounting surface 16 of thc troweling blade 12 and overlying the discharge openings 30, 32 and 34 is a longitudinally-extending plaster manifold 36 constituting part of a plaster distributing means of the invention for distributing plaster to the various discharge openings. One end of the manifold 36 is secured to the blade 12 by means of a clip 38 overlying the manifold and the reinforcing rib 18 and having a screw 40 threaded therethrough into the reinforcing rib. Overlying the 0pposite ends of the reinforcing rib 18 and the manifold 36, and seated against the manifold, is an angle clip 42 one arm of which bear-s against the mounting surface 16 of the troweling blade 12, as best shown in FIG. 5. A stud 44 carried by the reinforcing rib 18 projects through the angle clip 42 and has a wing nut 46 threaded thereonto. As will be apparent, by adjusting the wing nut 46, the force with which the adjacent portion of the manifold 36 is biased toward the mounting surface 16 may be adjusted, for a reason to be discussed.

The plaster distributing means of the invention comprises a selector valve means 48 within the manifold 36 for directing plaster entering the manifold to either the forward discharge opening 30 only, or to the intermediate and rearward discharge openings 32 and 34 simultaneously. The selector valve means 48 comprises a longitudinally-movable slide valve 50 which is seated against the mounting surface 16 of the troweling blade 12 and which has longitudinal edges snugly slidably engaging the longitudinal side walls of the manifold to prevent plaster leakage therebetween. The slide valve 50 is provided with an integral actuating tab 52 which projects laterally from one longitudinal edge of the slide valve toward the trailing edge 28 of the troweling blade 12 through a longitudinally-elongated notch 54 in the edge of the corresponding longitudinal side wall of the manifold 36. The length of the notch 54 is sufficient to permit the `necessary longitudinal travel of the slide valve 5t), which will be described hereinafter. The longitudinal edge of the notch 54 bears against the actuating tab 52 to prevent plaster leakage, the pressure with which it beats against the actuating tab being adjustable by means of the wing nut 46. Prefer-ably, this wing nut is yso adjusted as to prevent plaster leakage and as to maintain the slide valve 50 in the desired position. Projecting from the aetuating tab 52 of the slide valve 50 is a slide-valve actuating knob or pin 56 for moving the slide valve longitudinally.

The slide valve 50 is movable longitudinally of the manifold 36 between two extreme positions, respectively shown in FIGS. 3 and 4. The length of the slide valve 50 is such that when it is in its FIG. 3 position, it uncovers the forward discharge opening 30 and covers the rearward discharge opening 34. At the same time, it covers the intermediate discharge opening 32. Thus, under such conditions, all of plaster entering the mainfold 36 is delivered to the forward discharge opening 30, as when troweling adjacent an edge of a surface 'being plastered.

When the slide valve 50 is in its FIG. 4 or forward position, it covers the forward discharge opening 30 and uncovers the rearward discharge opening 34. At the same time, a notch or other opening 58 in the slide valve 50 registers with the intermediate discharge opening 32. Thus, under such conditions, the plaster entering the manifold 36 is discharged through the intermediate and rearward openings 32 and 34, as when troweling an area to be plastered remote from the edges of such area. If desired, the slide valve 50 may be placed in an intermediate position, not shown, wherein it partially uncovers all of the discharge openings 30, 32 and 34.

The manifold 36 is provided with an inlet fitting 60 through which plaster may flow into the interior of the manifold. As shown in FIGS. 3 and 4, inlet tting 60 communicates with the interior of the plaster manifold 36 between the intermediate and rearward discharge openings 32 and 34 and adjacent the intermediate discharge opening. With this positional arrangement, the plaster discharge through the smaller intermediate discharge opening 32 is substantially the same as that through the larger rearward discharge opening 34 when the slide valve S0 is in its FIG. 4 position,fdue tov the fact that the discharge opening 32 is closer to the inlet fitting '60 than the discharge opening 34 is. This location for the inlet fitting 60 also places it reasonably close to the forward discharge opening 30 to minimize flow losses when this opening is 1n use.

The plaster is delivered to the inlet fitting 60 through a plaster conduit 62 connected at one end to the inlet fitting, as by a lhose connection, and connected at its other end to a suitable source of plaster under pressure, such as a plaster pump, not shown. The plaster conduit includes a relatively short section 64 of low pressure hose connected at one end to the inlet fitting 60 and connected at its other end to a section of high pressure hose 66 extending to the plaster pump, or other source of plaster under pressure. The section 64 of low pressure hose is capable of yielding to provide adjacent the trowel a surge chamber for absorbing pressure surges, such as those due to starting a plaster pump to which the conduit 62 is connected. It will be understood that because of the pressure drop in the plaster conduit 62, the plaster pressure in the section of low pressure hose 64 is relatively low, as compared to the plaster pressure at the outlet of the plaster pump, or the like. Consequently, utilizing low pressure hose for the surge-chamber section 64 is acceptable.

Turning now to FIG. 7 of to the drawing, illustrated therein is a self-feeding trowel 110 of t-he invention which differs from the self-feeding trowel -10` primarily in that it includes a handle 120* carried by a plaster manifold 136, instead of a separate reinforcing rib as in the trowel 10.

More particularly, the trowel 110 includes a rectangular blade 112 having troweling and mounting surfaces 114 and 116. The blade 112 is provided with forward, intermediate and rearward discharge openings therethrough corresponding to the forward, intermediate and rearward discharge openings 30, 32 and 34, the forward discharge opening being designated by the numeral '130 in FIG. 7. Preferably, the discharge openings through the blade 112 are located on its longitudinal centerline.

The plaster manifold 136 overlies the discharge openings through the blade 112 and is provided along its longitudinal edges with fianges slidably inserted under longitudinally-extending clips 138 welded, or otherwise secured, to the mounting surface 116 of the blade 112. The plaster manifold 136 is fixed in position longitudinally of the clips 138 in any suitable manner, as by a suitable locking stud and nut, not shown.

Disposed between the plaster manifold 136 and the mounting surface 116 of the blade 112, and slidable longitudinally of the plaster manifold, is a slide valve 150 corresponding to the slide valve `50 of the trowel 10. The slide valve 150 is provided with a forward discharge opening 151 registering with the forward discharge opening 130 through the blade 112 in one longitudinal position of the slide valve. The slide valve 150 is provided with intermediate and rearward discharge openings, not shown, registering with the intermediate and rearward discharge openings through the blade 112 in another longitudinal position of the slide valve.

The slide valve =150 is provided with a laterally-extending actuating tab 152 which projects laterally through a longitudinally-extending notch 154 in the manifold 136. The actuating tab 152 terminates in an actuating knob 156.

The plaster manifold 136 is provided with an inlet fitting 160 corresponding to the inlet fitting l60 of the trowel 10. The handle 120 is secured to the inlet fittting 160, as by means of a bolt 161 welded, or otherwise secured, to the inlet fitting.

The operation of the self-feeding trowel 110 is essentially the same as that of the self-feeding trowel 10. Consequently, no further description of the self-feeding trowel 1x10 is necessary.

Although exemplary embodiments of the invention have been disclosed herein for purposes of illustration,

it will be understood that various changes, modifications and substitutions may be incorporated in such embodiments -without departing from the spirit of the invention as defined by the claims which follow.

I claim as my invention:

1. In a self-feeding trowel, the combination of:

(a) a generally rectangular troweling blade having a troweling surface on one side thereof;

(b) a handle on the opposite side of and connected to said blade;

(c) said blade having laterally spaced leading and trailing edges extending longitudinally thereof and longitudinally spaced forward and rearward edges extending laterally thereof;

(d) said troweling surface being provided therein with spaced plaster discharge openings located between and spaced from said leading and trailing edges of said blade and located different distances from and spaced from said forward edge thereof; and

(e) plaster distributing means on said opposite side of said blade for delivering plaster to said discharge openings selectively.

2. A self-feeding trowel according to claim 1 wherein said plaster distributing means includes selector valve means for opening and closing said discharge openings selectively.

3. A self-feeding trowel -as defined in claim 1 wherein said plaster distributing means includes:

(a) a plaster manifold mounted on said opposite side of said blade and communicating with said discharge openings;

(b) selector valve means in said plaster manifold for selectively opening and closing said discharge openings; and

(c) said plaster manifold being provided with a plaster inlet.

4. A self-feeding trowel as set forth in claim 3 including a plaster conduit connected to said plaster inlet, said plaster conduit having a portionV adjacent said plaster inlet which is more yieldable than the portion of said plaster conduit remote from said plaster inlet to provide a surge chamber adjacent said plaster inlet.

5. A self-feeding trowel as defined in claim 3 wherein said handle is connected to said plaster manifold.

6. A self-feeding trowel as defined in claim 1 wherein said discharge openings are aligned longitudinally of said troweling surface and include:

(a) a forward discharge opening adjacent said forward edge of said blade;

(b) a rearward discharge opening approximately midway between said forward and rearward edges of said blade; and

(c) an intermediate discharge opening intermediate said forward and rearward discharge openings.

7. A self-feeding trowel according to claim 6 wherein said plaster distributing means includes selector valve means for opening either said forward discharge opening, or said rearward and intermediate discharge openings.

8. A self-feeding trowel as defined in claim 7 wherein said plaster distributing means includes a longitudinallyextending plaster manifold mounted on said opposite side of said blade in communication with said discharge openings and provided with a plaster inlet between said rearward and intermediate discharge openings and adjacent said intermediate discharge opening.

9. A self-feeding trowel as defined in claim 7 wherein said plaster distributing means includes a longitudinallyextending plaster manifold mounted on said opposite side of said blade in communication with said discharge openings and provided with a plaster inlet, and wherein said selector valve means includes a slide valve disposed within and slidable longitudinally of said plaster manifold and slidably engaging said opposite side of said blade.

10. A self-feeding trowel as set forth in claim 6 wherein said longitudinally-spaced discharge openings are located in a region bounded by substantially the longitudinal centerline of said blade and said trailing edge thereof.

References Cited UNITED STATES PATENTS 8 Watkins et al. Ratlitf 15-594 DiMattia et al. 13S-30 Brown et al. l8-3.5

Diamond 15-595 Callahan 15-235.7

CHARLES A. WILMUTH, Primary Examiner.

R. I. SMITH, Assistant Examiner. 

